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Remove more volatile qualifiers.

Browse Source 
Prior to commit 0709b7ee72, access to
variables within a spinlock-protected critical section had to be done
through a volatile pointer, but that should no longer be necessary.
This continues work begun in df4077cda2
and 6ba4ecbf47.

Thomas Munro and Michael Paquier
This commit is contained in:
Robert Haas
2015-10-06 15:45:02 -04:00
parent b943f502b7
commit 8f6bb851bd
6 changed files with 108 additions and 182 deletions
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49
src/backend/replication/logical/logical.c
View File

@ -848,16 +848,13 @@ LogicalConfirmReceivedLocation(XLogRecPtr lsn)
bool updated_xmin = false;
bool updated_restart = false;
/* use volatile pointer to prevent code rearrangement */
volatile ReplicationSlot *slot = MyReplicationSlot;
SpinLockAcquire(&MyReplicationSlot->mutex);
SpinLockAcquire(&slot->mutex);
slot->data.confirmed_flush = lsn;
MyReplicationSlot->data.confirmed_flush = lsn;
/* if were past the location required for bumping xmin, do so */
if (slot->candidate_xmin_lsn != InvalidXLogRecPtr &&
slot->candidate_xmin_lsn <= lsn)
if (MyReplicationSlot->candidate_xmin_lsn != InvalidXLogRecPtr &&
MyReplicationSlot->candidate_xmin_lsn <= lsn)
{
/*
* We have to write the changed xmin to disk *before* we change
@ -868,28 +865,28 @@ LogicalConfirmReceivedLocation(XLogRecPtr lsn)
* ->effective_xmin once the new state is synced to disk. After a
* crash ->effective_xmin is set to ->xmin.
*/
if (TransactionIdIsValid(slot->candidate_catalog_xmin) &&
slot->data.catalog_xmin != slot->candidate_catalog_xmin)
if (TransactionIdIsValid(MyReplicationSlot->candidate_catalog_xmin) &&
MyReplicationSlot->data.catalog_xmin != MyReplicationSlot->candidate_catalog_xmin)
{
slot->data.catalog_xmin = slot->candidate_catalog_xmin;
slot->candidate_catalog_xmin = InvalidTransactionId;
slot->candidate_xmin_lsn = InvalidXLogRecPtr;
MyReplicationSlot->data.catalog_xmin = MyReplicationSlot->candidate_catalog_xmin;
MyReplicationSlot->candidate_catalog_xmin = InvalidTransactionId;
MyReplicationSlot->candidate_xmin_lsn = InvalidXLogRecPtr;
updated_xmin = true;
}
}
if (slot->candidate_restart_valid != InvalidXLogRecPtr &&
slot->candidate_restart_valid <= lsn)
if (MyReplicationSlot->candidate_restart_valid != InvalidXLogRecPtr &&
MyReplicationSlot->candidate_restart_valid <= lsn)
{
Assert(slot->candidate_restart_lsn != InvalidXLogRecPtr);
Assert(MyReplicationSlot->candidate_restart_lsn != InvalidXLogRecPtr);
slot->data.restart_lsn = slot->candidate_restart_lsn;
slot->candidate_restart_lsn = InvalidXLogRecPtr;
slot->candidate_restart_valid = InvalidXLogRecPtr;
MyReplicationSlot->data.restart_lsn = MyReplicationSlot->candidate_restart_lsn;
MyReplicationSlot->candidate_restart_lsn = InvalidXLogRecPtr;
MyReplicationSlot->candidate_restart_valid = InvalidXLogRecPtr;
updated_restart = true;
}
SpinLockRelease(&slot->mutex);
SpinLockRelease(&MyReplicationSlot->mutex);
/* first write new xmin to disk, so we know whats up after a crash */
if (updated_xmin || updated_restart)
@ -907,9 +904,9 @@ LogicalConfirmReceivedLocation(XLogRecPtr lsn)
*/
if (updated_xmin)
{
SpinLockAcquire(&slot->mutex);
slot->effective_catalog_xmin = slot->data.catalog_xmin;
SpinLockRelease(&slot->mutex);
SpinLockAcquire(&MyReplicationSlot->mutex);
MyReplicationSlot->effective_catalog_xmin = MyReplicationSlot->data.catalog_xmin;
SpinLockRelease(&MyReplicationSlot->mutex);
ReplicationSlotsComputeRequiredXmin(false);
ReplicationSlotsComputeRequiredLSN();
@ -917,10 +914,8 @@ LogicalConfirmReceivedLocation(XLogRecPtr lsn)
}
else
{
volatile ReplicationSlot *slot = MyReplicationSlot;
SpinLockAcquire(&slot->mutex);
slot->data.confirmed_flush = lsn;
SpinLockRelease(&slot->mutex);
SpinLockAcquire(&MyReplicationSlot->mutex);
MyReplicationSlot->data.confirmed_flush = lsn;
SpinLockRelease(&MyReplicationSlot->mutex);
}
}